Peter Blake in his seventies is getting an opportunity that comes to few people, artists or not. He has designed the cover of the new Oasis compilation album, but that's not what makes him lucky. He's also got his art on Pizza Express boxes, but that's not what makes him special. Look closely at his Oasis design; it is a completely backward-looking, nostalgic restatement of very early pop art, complete with Elvis, pinups, and badges - all the Americana he was in love with as a young man in the 1950s. Peter Blake in old age has taken the opportunity to remind the world of his early achievements.

The reason Blake still holds cachet as a pop artist is that he did the cover of Sergeant Pepper's Lonely Hearts Club Band yet his new cover does not play on the Beatles connection. Instead it leapfrogs back further in time to a world before The Beatles, when he was almost alone in championing Pop imagery. You get the impression of a contented old man who knows the value of what he has done.

I thought of Blake, to be honest, as a complacent establishment hack, who has lived brilliantly off his past. Then this morning I looked at the Oasis cover, dug out the art history books, and felt admiration. Blake was one of the really original British artists of the last century; a visionary of a kind. Paintings such as On the Balcony (1955-7) feature teenagers before the "teenager" had reached this country - they are portraits of the avant-garde of what was to become the 60s. They anticipate the lyricism of the best British pop music - his aural equivalent incidentally being not The Beatles but The Who. Look at his images of people wearing Elvis badges; listen to The Who's Tattoo.

Honestly, I can't think of a harsh thing to say about Peter Blake. Can you?